Microsoft’s Hotmail has been the most popular online email service for the past 15 years. It has 350 million users and they’re not going anywhere.

Microsoft has now added a feature that Google’s Gmail has had for sometime: the ability to use Hotmail without changing your old email address. To the recipient of your message, the email still appears to come from your other email account, if you want to hold on to that.

One of the best Hotmail features is its ability to send really large photos – up to ten gigabytes — without adding them an attachment. A small version of each photo appears in the email, and if the recipient wants to see the full picture, they click on a link. Microsoft claims you can send a hundred photos in each email this way, no matter what their size. (We haven’t tried sending a hundred, but groups of a few dozen went out all right.) The photos are automatically stored in a free private storage area called “SkyDrive.” If you’d prefer to send them as attachments, you can still do that and the recipient would click to bring them up. Remember though: a large photo can take up a lot of memory and transmission time, and not everybody is equipped to handle that. Click on a menu to compress the files.

Hotmail contains the Microsoft search engine, “Bing.” They have thousands of beautiful photos and you can send these directly from Hotmail. This can be for fun or to cover a sin of omission. For instance, if you didn’t take any photos of your recent trip to Chicago, just pick that location and Bing will load in a selection. There’s a Bing search box off to one side of the screen, and when you find images you like, just click to add them to your email.

Hotmail also has “Sweep.” You can sweep a whole group of emails into a folder at once, or delete them in one fell swoop. This is very nice but it’s too bad Microsoft makes their software so tech-y. It’s always been this way (and we’ve been looking at their software for more than 30 years) so it must be something deep in their culture. For example, our first problem was trying to import all our Gmail contacts into Hotmail. We tried importing all 5,367 of them, but Hotmail said the file was too big. Okay, that’s understandable. But when we tried sending just 252 of our nearest and dearest, we got the response that the file was still too big. Finally, Hotmail accepted 82 of them. Then we discovered the automatic import, available when you click “contacts” and “manage,” but only a thousand of our 5,367 contacts came in.

Another minus: If you use Hotmail’s “SkyDrive” link to send lots of photos, the recipient can view them online but cannot download them unless you send them an invitation to be your friend or change your privacy settings to make all photos public. Otherwise they get an error message saying those photos are off limits. On the plus side, it was nice that you can play the incoming photos as a slideshow if you wish.

Links on the left of the Hotmail window can take you to any documents or photos you’ve stored online. Click on “Windows Live” and then “SkyDrive” at the top of the screen to see what you have in storage. Click “Office” to use their free online word processor and some other programs.

If this all seems too complicated and all you want to do is share photos online, we recommend Google’s “Picasa Web Albums.” Yousendit.com is another free service that works well. To send and encrypt very large files and photos, there’s the new WinZip Courier, which works right from your email inbox; it’s $25 from winzip.com.